Controller Wiring Question (Switching from a 4 lug to 6 lug Controller)

[MaineUSA]

All,

My present controller wiring only has 4 connection lug points (2 + and 2 - terminals) for “Solar” and “Battery.”

I am buying a new controller with 6 lug connection points (3 positive+ and 3 negative – terminals) = “Solar,” “Battery” and “Load.”

Question: How do I wire the new 3 connection controller with 3 + positive and 3 - negative lugs, when I only have 4 actual copper wires (2 from the battery and 2 from the solar panels) to connect to the new controller please?

Note: The new controller is from Harbor Freight Thunderbolt Magnum Solar - item#68738. The old controller is a Sunforce 30 amp model #60032.

Support appreciated!

[inetdog]

All,

My present controller wiring only has 4 connection lug points (2 + and 2 - terminals) for “Solar” and “Battery.”

I am buying a new controller with 6 lug connection points (3 positive+ and 3 negative – terminals) = “Solar,” “Battery” and “Load.”

Question: How do I wire the new 3 connection controller with 3 + positive and 3 - negative lugs, when I only have 4 actual copper wires (2 from the battery and 2 from the solar panels) to connect to the new controller please?

Note: The new controller is from Harbor Freight Thunderbolt Magnum Solar - item#68738. The old controller is a Sunforce 30 amp model #60032.

Support appreciated!

Just ignore the Load terminals completely.

If at some point in the future you want to connect a low power load to only run when the batteries are close to fully charged you can connect that load to the Load terminals.
DO NOT try to connect an inverter to the Load terminals.

[Sunking]

Load terminal is pretty much useless. It is a very low power terminal that is connected to the battery through a low voltage disconnect relay.

[SunEagle]

Load terminal is pretty much useless. It is a very low power terminal that is connected to the battery through a low voltage disconnect relay.

I always wondered what the thought process was including those "load" terminals. Did the manufacturer think everyone may want to add a low wattage dc light so they can see thier system at night?

When I purchased my folding solar panel it came with one of those cheap Eco-Worthy 15 amp charge controllers. In the "manual" it mentions something about the timer and light sensor is adjustable. I think this means you can connect some "dc lights" to the load terminals and then set the time when the lights should come on and for how long. Both of those timing functions are setable using the 8 posistion dip switch inside the controller.

While it doesn't say clearly I would suspect the Manufacturer excepts you to charge a battery with the solar panels and then use these timing functions to power lighting from the battery through the charge controller.

[Mike90250]

Come controllers have "Lighting Features" for sunset or dawn, or 3 hours after sunset. A small load connects to the LOAD terminals in that case. Otherwise, ignore them.

You might want to skip the learning process (most of HF gear is not that good if you are trying to really get it to do it's intended job) and get a small controller from the Morningstar line.

[inetdog]

Some controllers have "Lighting Features" for sunset or dawn, or 3 hours after sunset. A small load connects to the LOAD terminals in that case. Otherwise, ignore them.

You might want to skip the learning process (most of HF gear is not that good if you are trying to really get it to do it's intended job) and get a small controller from the Morningstar line.

Many of these are marketed specifically as "solar lighting controllers" rather than "soar charge controllers". For the ones which do not have any lighting control features, the only use for the Load terminals, as Sunking indicated, is to provide a low voltage disconnect feature for a small DC load that does not include an LVD of its own.
However the low voltage threshold (at least the initial setting if programmable) is usually far too low for good battery health. And the available power is too low for most non-lighting uses.

[MaineUSA]

Many Thanks!

All, Your good advice appreciated! I bought a Morningstar 30 Amp controller today. The auto shut down feature is a huge bonus.